Early chemoprophylaxis is associated with decreased venous thromboembolism risk without concomitant increase in intraspinal hematoma expansion after traumatic spinal cord injury

Abstract

Background After traumatic spinal cord injury (SCI), there is increased risk of venous thromboembolism (VTE), but chemoprophylaxis (PPX) may cause expansion of intraspinal hematoma (ISH). Methods Single-center retrospective study of adult trauma patients from 2012–2015 with SCI. Exclusion criteria: VTE diagnosis, death, or discharge within 48 hours. Patients were dichotomized based on early (≤48 hours) heparinoid and/or aspirin PPX. ISH expansion was diagnosed intraoperatively or by follow-up radiology. We used multivariable Cox proportional hazards to estimate the effect of PPX on risk of VTE and ISH expansion controlling for age, ISS, complete SCI, and mechanism as static covariates and operative spine procedure as a time-varying covariate. Results 501 patients with SCI were dichotomized into early PPX (n=260, 52%) and no early PPX (n=241, 48%). Early PPX patients were less likely blunt-injured (91% vs 97%) and had fewer operative spine interventions (65% vs 80%), but age (median 43 vs 49 years), ISS (median 24 vs 21), admission ISH (47% vs 44%), and VTE (5% vs 9%) were similar. Cox analysis found that early heparinoids was associated with reduced VTE (HR 0.37, 95% CI 0.16–0.84) and reduced pulmonary embolism (PE) (HR 0.20, 95% CI 0.06–0.69). The estimated number needed to treat with heparinoids was 10 to prevent one VTE and 13 to prevent one PE at 30 days. Early aspirin was not associated with reduced VTE or PE. Seven patients (1%) had ISH expansion, of which 4 were on PPX at time of expansion. Using heparinoid and aspirin as time-varying covariates, neither heparinoids (HR 1.90, 95% CI 0.32–11.41) nor aspirin (HR 3.67, 95% CI 0.64–20.88) was associated with ISH expansion. Conclusion Early heparinoid therapy was associated with decreased VTE and PE risk in SCI patients without concomitant increase in ISH expansion. Level of Evidence Level IV (Therapeutic)

Venous Thromboembolism Chemoprophylaxis Within 24 Hours of Surgery for Spinal Cord Injury: Is It Safe and Effective?

“…Duplex ultrasound was performed if there was clinical suspicion for DVT/PE. 11,17,26,28,31,38 Routine duplex ultrasounds were not obtained due to the increased cost and resource utilization required for obtaining the study in all SCI patients. PE was confirmed with computed tomography angiography.…”

“…9 Notably, long-term mortality has not decreased in this population over the past 3 decades. 10 Anticoagulation with heparinoid chemoprophylaxis has been utilized as an effective strategy to safely decrease VTE in SCI patients [11][12][13] with both unfractionated heparin (UFH) [14][15][16] and low molecular weight heparin (LMWH) 8,17 being most studied, and at various doses. 18 Mechanical prophylaxis has been shown to augment the effect of chemical prophylaxis, 16,19,20 but prophylaxis with inferior vena cava (IVC) filters has been associated with higher rates of deep vein thrombosis (DVT) in acute SCI patients.…”

“…There is some evidence in the literature that chemoprophylaxis closer to the time of injury is associated with lower rates of DVT and VTE. 11,16,17,23,24,[35][36][37][38] Several systematic reviews have subsequently recommended for the strategy of chemoprophylaxis within 72 hours of SCI 13,19,32 including guidelines published by the American Association of Neurological Surgeons/Congress of Neurological Surgeons in 2013, which gave a level II recommendation. 19,35 The purpose of this study is to investigate the effectiveness and safety of initiating early VTE chemoprophylaxis within 24 hours of SCI in a surgical cohort by comparing the outcomes of individuals who received chemoprophylaxis within 24 hours of injury to those between 24 and 72 hours, and after 72 hours.…”

When and if to stop low-dose aspirin before spine surgery?

“…Multiple studies demonstrated the relative increased hemorrhagic risks/complications of performing spinal surgery while continuing LD-ASA or just stopping LD-ASA for 3–7 days prior to SS; notably, several other studies also indicated no such risks if LD-ASA was stopped for >7–10 days [Tables 1 and 2 ]. [ 1 2 3 4 5 6 7 8 9 10 ] As a spine surgeon who wants to avoid an intraspinal hematoma and irreversible neurological injury, my bias would be to stop ASA at least 7–10 days prior to SS (e.g., more toward day 10). Notably, these studies were of variable quality (e.g., no adequate randomized controlled trials), and came to different conclusions.…”

“…[ Table 2 ]. [ 1 ] Although mini-heparin reduced the incidence of DVT/PE, LD-ASA did not. Of interest, neither mini-heparin or LD-ASA contributed to clot expansion in 7% of the patients who originally presented with SCI-related intraspinal hematomas.…”